[PATCH v3 3/6] drm: Move nomodeset kernel parameter to the DRM subsystem

[Javier Martinez Canillas <javierm@xxxxxxxxxx>]

The "nomodeset" kernel cmdline parameter is handled by the vgacon driver
but the exported vgacon_text_force() symbol is only used by DRM drivers.

It makes much more sense for the parameter logic to be in the subsystem
of the drivers that are making use of it.

Let's move the vgacon_text_force() function and related logic to the DRM
subsystem. While doing that, rename the function to drm_get_modeset() and
make it return true if modesetting is enabled and false otherwise. This
better reflects the condition that drivers are actually testing for.

Suggested-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
---

Changes in v3:
- Drop the drm_drv_enabled() function and just call to drm_get_modeset().
- Make drm_get_modeset() just a getter function and don't return an error.
- Move independent cleanups in drivers as separate preparatory patches.

Changes in v2:
- Conditionally build drm_nomodeset.o if CONFIG_VGA_CONSOLE is set.
- Squash patches to move nomodeset logic to DRM and do the renaming.
- Name the function drm_check_modeset() and make it return -ENODEV.
- Squash patch to add drm_drv_enabled() and make drivers use it.
- Make the drivers changes before moving nomodeset logic to DRM.
- Make drm_drv_enabled() return an errno and -ENODEV if nomodeset.
- Remove debug and error messages in drivers.

 drivers/gpu/drm/Makefile                |  2 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  4 ++--
 drivers/gpu/drm/ast/ast_drv.c           |  4 ++--
 drivers/gpu/drm/drm_nomodeset.c         | 26 +++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_module.c      |  4 ++--
 drivers/gpu/drm/mgag200/mgag200_drv.c   |  4 ++--
 drivers/gpu/drm/nouveau/nouveau_drm.c   |  4 ++--
 drivers/gpu/drm/qxl/qxl_drv.c           |  4 ++--
 drivers/gpu/drm/radeon/radeon_drv.c     |  4 ++--
 drivers/gpu/drm/tiny/bochs.c            |  4 ++--
 drivers/gpu/drm/tiny/cirrus.c           |  5 +++--
 drivers/gpu/drm/vboxvideo/vbox_drv.c    |  4 ++--
 drivers/gpu/drm/virtio/virtgpu_drv.c    |  4 ++--
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c     |  4 ++--
 drivers/video/console/vgacon.c          | 21 --------------------
 include/drm/drm_mode_config.h           |  6 ++++++
 include/linux/console.h                 |  6 ------
 17 files changed, 59 insertions(+), 51 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_nomodeset.c

diff --git drivers/gpu/drm/Makefile drivers/gpu/drm/Makefile
index 1c41156deb5f..c74810c285af 100644
--- drivers/gpu/drm/Makefile
+++ drivers/gpu/drm/Makefile
@@ -33,6 +33,8 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o drm_privacy_screen_x86.
 
 obj-$(CONFIG_DRM_DP_AUX_BUS) += drm_dp_aux_bus.o
 
+obj-$(CONFIG_VGA_CONSOLE) += drm_nomodeset.o
+
 drm_cma_helper-y := drm_gem_cma_helper.o
 obj-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_cma_helper.o
 
diff --git drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 289d04999ced..0da7f0b14700 100644
--- drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -28,10 +28,10 @@
 #include <drm/drm_gem.h>
 #include <drm/drm_vblank.h>
 #include <drm/drm_managed.h>
+#include <drm/drm_mode_config.h>
 #include "amdgpu_drv.h"
 
 #include <drm/drm_pciids.h>
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/vga_switcheroo.h>
@@ -2514,7 +2514,7 @@ static int __init amdgpu_init(void)
 {
 	int r;
 
-	if (vgacon_text_force())
+	if (!drm_get_modeset())
 		return -EINVAL;
 
 	r = amdgpu_sync_init();
diff --git drivers/gpu/drm/ast/ast_drv.c drivers/gpu/drm/ast/ast_drv.c
index 86d5cd7b6318..e788deac15cb 100644
--- drivers/gpu/drm/ast/ast_drv.c
+++ drivers/gpu/drm/ast/ast_drv.c
@@ -26,7 +26,6 @@
  * Authors: Dave Airlie <airlied@xxxxxxxxxx>
  */
 
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 
@@ -35,6 +34,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_gem_vram_helper.h>
+#include <drm/drm_mode_config.h>
 #include <drm/drm_probe_helper.h>
 
 #include "ast_drv.h"
@@ -233,7 +233,7 @@ static struct pci_driver ast_pci_driver = {
 
 static int __init ast_init(void)
 {
-	if (vgacon_text_force() && ast_modeset == -1)
+	if (!drm_get_modeset() && ast_modeset == -1)
 		return -EINVAL;
 
 	if (ast_modeset == 0)
diff --git drivers/gpu/drm/drm_nomodeset.c drivers/gpu/drm/drm_nomodeset.c
new file mode 100644
index 000000000000..fc3acf3ab2e2
--- /dev/null
+++ drivers/gpu/drm/drm_nomodeset.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/module.h>
+#include <linux/types.h>
+
+static bool drm_nomodeset;
+
+bool drm_get_modeset(void)
+{
+	return !drm_nomodeset;
+}
+EXPORT_SYMBOL(drm_get_modeset);
+
+static int __init disable_modeset(char *str)
+{
+	drm_nomodeset = true;
+
+	pr_warn("You have booted with nomodeset. This means your GPU drivers are DISABLED\n");
+	pr_warn("Any video related functionality will be severely degraded, and you may not even be able to suspend the system properly\n");
+	pr_warn("Unless you actually understand what nomodeset does, you should reboot without enabling it\n");
+
+	return 1;
+}
+
+/* Disable kernel modesetting */
+__setup("nomodeset", disable_modeset);
diff --git drivers/gpu/drm/i915/i915_module.c drivers/gpu/drm/i915/i915_module.c
index ab2295dd4500..f952e8b69465 100644
--- drivers/gpu/drm/i915/i915_module.c
+++ drivers/gpu/drm/i915/i915_module.c
@@ -4,7 +4,7 @@
  * Copyright © 2021 Intel Corporation
  */
 
-#include <linux/console.h>
+#include <drm/drm_mode_config.h>
 
 #include "gem/i915_gem_context.h"
 #include "gem/i915_gem_object.h"
@@ -31,7 +31,7 @@ static int i915_check_nomodeset(void)
 	if (i915_modparams.modeset == 0)
 		use_kms = false;
 
-	if (vgacon_text_force() && i915_modparams.modeset == -1)
+	if (!drm_get_modeset() && i915_modparams.modeset == -1)
 		use_kms = false;
 
 	if (!use_kms) {
diff --git drivers/gpu/drm/mgag200/mgag200_drv.c drivers/gpu/drm/mgag200/mgag200_drv.c
index 6b9243713b3c..3df5a608d0e7 100644
--- drivers/gpu/drm/mgag200/mgag200_drv.c
+++ drivers/gpu/drm/mgag200/mgag200_drv.c
@@ -6,7 +6,6 @@
  *          Dave Airlie
  */
 
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/vmalloc.h>
@@ -15,6 +14,7 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_ioctl.h>
+#include <drm/drm_mode_config.h>
 #include <drm/drm_pciids.h>
 
 #include "mgag200_drv.h"
@@ -378,7 +378,7 @@ static struct pci_driver mgag200_pci_driver = {
 
 static int __init mgag200_init(void)
 {
-	if (vgacon_text_force() && mgag200_modeset == -1)
+	if (!drm_get_modeset() && mgag200_modeset == -1)
 		return -EINVAL;
 
 	if (mgag200_modeset == 0)
diff --git drivers/gpu/drm/nouveau/nouveau_drm.c drivers/gpu/drm/nouveau/nouveau_drm.c
index 1f828c9f691c..d42e07de6460 100644
--- drivers/gpu/drm/nouveau/nouveau_drm.c
+++ drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -22,7 +22,6 @@
  * Authors: Ben Skeggs
  */
 
-#include <linux/console.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -34,6 +33,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_gem_ttm_helper.h>
 #include <drm/drm_ioctl.h>
+#include <drm/drm_mode_config.h>
 #include <drm/drm_vblank.h>
 
 #include <core/gpuobj.h>
@@ -1322,7 +1322,7 @@ nouveau_drm_init(void)
 	nouveau_display_options();
 
 	if (nouveau_modeset == -1) {
-		if (vgacon_text_force())
+		if (!drm_get_modeset())
 			nouveau_modeset = 0;
 	}
 
diff --git drivers/gpu/drm/qxl/qxl_drv.c drivers/gpu/drm/qxl/qxl_drv.c
index fc47b0deb021..2d87a95ae431 100644
--- drivers/gpu/drm/qxl/qxl_drv.c
+++ drivers/gpu/drm/qxl/qxl_drv.c
@@ -29,7 +29,6 @@
 
 #include "qxl_drv.h"
 
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/vgaarb.h>
@@ -40,6 +39,7 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_gem_ttm_helper.h>
+#include <drm/drm_mode_config.h>
 #include <drm/drm_modeset_helper.h>
 #include <drm/drm_prime.h>
 #include <drm/drm_probe_helper.h>
@@ -295,7 +295,7 @@ static struct drm_driver qxl_driver = {
 
 static int __init qxl_init(void)
 {
-	if (vgacon_text_force() && qxl_modeset == -1)
+	if (!drm_get_modeset() && qxl_modeset == -1)
 		return -EINVAL;
 
 	if (qxl_modeset == 0)
diff --git drivers/gpu/drm/radeon/radeon_drv.c drivers/gpu/drm/radeon/radeon_drv.c
index 380adc61e71c..802a28d55d0a 100644
--- drivers/gpu/drm/radeon/radeon_drv.c
+++ drivers/gpu/drm/radeon/radeon_drv.c
@@ -31,7 +31,6 @@
 
 
 #include <linux/compat.h>
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/vga_switcheroo.h>
@@ -45,6 +44,7 @@
 #include <drm/drm_file.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_ioctl.h>
+#include <drm/drm_mode_config.h>
 #include <drm/drm_pciids.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
@@ -637,7 +637,7 @@ static struct pci_driver radeon_kms_pci_driver = {
 
 static int __init radeon_module_init(void)
 {
-	if (vgacon_text_force() && radeon_modeset == -1)
+	if (!drm_get_modeset() && radeon_modeset == -1)
 		radeon_modeset = 0;
 
 	if (radeon_modeset == 0)
diff --git drivers/gpu/drm/tiny/bochs.c drivers/gpu/drm/tiny/bochs.c
index 2ce3bd903b70..500101f8a6e9 100644
--- drivers/gpu/drm/tiny/bochs.c
+++ drivers/gpu/drm/tiny/bochs.c
@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-#include <linux/console.h>
 #include <linux/pci.h>
 
 #include <drm/drm_aperture.h>
@@ -11,6 +10,7 @@
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_gem_vram_helper.h>
 #include <drm/drm_managed.h>
+#include <drm/drm_mode_config.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
 
@@ -719,7 +719,7 @@ static struct pci_driver bochs_pci_driver = {
 
 static int __init bochs_init(void)
 {
-	if (vgacon_text_force() && bochs_modeset == -1)
+	if (!drm_get_modeset() && bochs_modeset == -1)
 		return -EINVAL;
 
 	if (bochs_modeset == 0)
diff --git drivers/gpu/drm/tiny/cirrus.c drivers/gpu/drm/tiny/cirrus.c
index 4611ec408506..c94a030b6b3b 100644
--- drivers/gpu/drm/tiny/cirrus.c
+++ drivers/gpu/drm/tiny/cirrus.c
@@ -16,7 +16,6 @@
  * Copyright 1999-2001 Jeff Garzik <jgarzik@xxxxxxxxx>
  */
 
-#include <linux/console.h>
 #include <linux/dma-buf-map.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -39,6 +38,7 @@
 #include <drm/drm_gem_shmem_helper.h>
 #include <drm/drm_ioctl.h>
 #include <drm/drm_managed.h>
+#include <drm/drm_mode_config.h>
 #include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
@@ -636,8 +636,9 @@ static struct pci_driver cirrus_pci_driver = {
 
 static int __init cirrus_init(void)
 {
-	if (vgacon_text_force())
+	if (!drm_get_modeset())
 		return -EINVAL;
+
 	return pci_register_driver(&cirrus_pci_driver);
 }
 
diff --git drivers/gpu/drm/vboxvideo/vbox_drv.c drivers/gpu/drm/vboxvideo/vbox_drv.c
index fd7abb029c65..74b8c93a664f 100644
--- drivers/gpu/drm/vboxvideo/vbox_drv.c
+++ drivers/gpu/drm/vboxvideo/vbox_drv.c
@@ -7,7 +7,6 @@
  *          Michael Thayer <michael.thayer@xxxxxxxxxx,
  *          Hans de Goede <hdegoede@xxxxxxxxxx>
  */
-#include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/vt_kern.h>
@@ -19,6 +18,7 @@
 #include <drm/drm_file.h>
 #include <drm/drm_ioctl.h>
 #include <drm/drm_managed.h>
+#include <drm/drm_mode_config.h>
 
 #include "vbox_drv.h"
 
@@ -193,7 +193,7 @@ static const struct drm_driver driver = {
 
 static int __init vbox_init(void)
 {
-	if (vgacon_text_force() && vbox_modeset == -1)
+	if (!drm_get_modeset() && vbox_modeset == -1)
 		return -EINVAL;
 
 	if (vbox_modeset == 0)
diff --git drivers/gpu/drm/virtio/virtgpu_drv.c drivers/gpu/drm/virtio/virtgpu_drv.c
index 749db18dcfa2..6ad20c225eed 100644
--- drivers/gpu/drm/virtio/virtgpu_drv.c
+++ drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -27,7 +27,6 @@
  */
 
 #include <linux/module.h>
-#include <linux/console.h>
 #include <linux/pci.h>
 #include <linux/poll.h>
 #include <linux/wait.h>
@@ -37,6 +36,7 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
+#include <drm/drm_mode_config.h>
 
 #include "virtgpu_drv.h"
 
@@ -104,7 +104,7 @@ static int virtio_gpu_probe(struct virtio_device *vdev)
 	struct drm_device *dev;
 	int ret;
 
-	if (vgacon_text_force() && virtio_gpu_modeset == -1)
+	if (!drm_get_modeset() && virtio_gpu_modeset == -1)
 		return -EINVAL;
 
 	if (virtio_gpu_modeset == 0)
diff --git drivers/gpu/drm/vmwgfx/vmwgfx_drv.c drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index ab9a1750e1df..049fd017dca5 100644
--- drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -25,7 +25,6 @@
  *
  **************************************************************************/
 
-#include <linux/console.h>
 #include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -34,6 +33,7 @@
 #include <drm/drm_aperture.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_ioctl.h>
+#include <drm/drm_mode_config.h>
 #include <drm/drm_sysfs.h>
 #include <drm/ttm/ttm_bo_driver.h>
 #include <drm/ttm/ttm_range_manager.h>
@@ -1651,7 +1651,7 @@ static int __init vmwgfx_init(void)
 {
 	int ret;
 
-	if (vgacon_text_force())
+	if (!drm_get_modeset())
 		return -EINVAL;
 
 	ret = pci_register_driver(&vmw_pci_driver);
diff --git drivers/video/console/vgacon.c drivers/video/console/vgacon.c
index ef9c57ce0906..d4320b147956 100644
--- drivers/video/console/vgacon.c
+++ drivers/video/console/vgacon.c
@@ -97,30 +97,9 @@ static int 		vga_video_font_height;
 static int 		vga_scan_lines		__read_mostly;
 static unsigned int 	vga_rolled_over; /* last vc_origin offset before wrap */
 
-static bool vgacon_text_mode_force;
 static bool vga_hardscroll_enabled;
 static bool vga_hardscroll_user_enable = true;
 
-bool vgacon_text_force(void)
-{
-	return vgacon_text_mode_force;
-}
-EXPORT_SYMBOL(vgacon_text_force);
-
-static int __init text_mode(char *str)
-{
-	vgacon_text_mode_force = true;
-
-	pr_warn("You have booted with nomodeset. This means your GPU drivers are DISABLED\n");
-	pr_warn("Any video related functionality will be severely degraded, and you may not even be able to suspend the system properly\n");
-	pr_warn("Unless you actually understand what nomodeset does, you should reboot without enabling it\n");
-
-	return 1;
-}
-
-/* force text mode - used by kernel modesetting */
-__setup("nomodeset", text_mode);
-
 static int __init no_scroll(char *str)
 {
 	/*
diff --git include/drm/drm_mode_config.h include/drm/drm_mode_config.h
index 48b7de80daf5..f4d407908348 100644
--- include/drm/drm_mode_config.h
+++ include/drm/drm_mode_config.h
@@ -969,4 +969,10 @@ static inline int drm_mode_config_init(struct drm_device *dev)
 void drm_mode_config_reset(struct drm_device *dev);
 void drm_mode_config_cleanup(struct drm_device *dev);
 
+#ifdef CONFIG_VGA_CONSOLE
+extern bool drm_get_modeset(void);
+#else
+static inline bool drm_get_modeset(void) { return true; }
+#endif
+
 #endif
diff --git include/linux/console.h include/linux/console.h
index 20874db50bc8..d4dd8384898b 100644
--- include/linux/console.h
+++ include/linux/console.h
@@ -217,12 +217,6 @@ extern atomic_t ignore_console_lock_warning;
 #define VESA_HSYNC_SUSPEND      2
 #define VESA_POWERDOWN          3
 
-#ifdef CONFIG_VGA_CONSOLE
-extern bool vgacon_text_force(void);
-#else
-static inline bool vgacon_text_force(void) { return false; }
-#endif
-
 extern void console_init(void);
 
 /* For deferred console takeover */
-- 
2.33.1